


A New Course

by darkspine10



Series: Falls Tales [1]
Category: Gravity Falls
Genre: Aged-Up Character(s), Beach City, Betrayal, Bows & Arrows, Dipper and Mabel solving mysteries, Intrigue, Investigations, Maps, Missing Persons, Mystery, Mythical Beings & Creatures, Research, Reunions, Sea Monsters, Twins, monster hunting
Language: English
Status: Completed
Published: 2020-07-10
Updated: 2020-08-03
Packaged: 2021-03-05 00:21:41
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 6
Words: 18,811
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/25185523
Author URL: https://archiveofourown.org/users/darkspine10/pseuds/darkspine10
Summary: People are going missing from the beach town of Sapphire Bay. College students vanishing by the dozen with no obvious cause. Dark spectres haunt the forests and beaches, but no-one in town wants to talk about it.May Pines, renowned activist and trouble-maker, has made it her mission to save the town. Calling on the help of her brother, the twins must reunite to work together to solve the mysteries of Sapphire Bay.
Series: Falls Tales [1]
Series URL: https://archiveofourown.org/series/1914031
Kudos: 10





	1. Familiar Ground

**Author's Note:**

> After finishing my last major GF project, I decided to return with a more manageable project that wouldn't take me 8 months to write. This is a blend of individual episodic stories and longer, arc-heavy plotting, creating a single overarching story. I may end up eventually writing further shorter fics like this, loosely tying them together, but for now here's the first of that experiment for you to enjoy.
> 
> Note: This story is set in the same continuity as my previous fics, The Mystery Teens and Forever Falling, though the connections are limited to minor references and the story is meant to be standalone and understandable without having read any prior fics.

The small beachfront house stood alone at the barrier between forest and sand. Waves lazily sprayed against the beach out below the house which hung over a small slope. From behind, the leaves of the trees rustled, a soft wind blowing in from the sea. Stepping out into the sunset light, Dipper Pines shielded his eyes and spotted a reclining figure on the wooden balcony.

Shutting the car door, he gave a deep sigh. This was still something he wasn’t yet fully used to. Meeting up with his sister as a regular thing, rather than it being an aberration. Time and new perspectives had healed the cracks that had led to their separation, but it still took some adjustments to his mindset.

Forgetting his initial wariness, he strode over and yelled out. “Mabel! I’m round the front!”

Out on the balcony her saw her stir – or fumble to get up rather – and disappear inside. He took a last look at the surroundings, building up a picture of where he’d be based for the foreseeable future. It would help to know every little detail, so any differences would stand out all the more clearly.

The wall of dark trees inland was much like what he knew from Gravity Falls, but the unmistakeable tang of salt ever-present in the air made him aware of the Pacific just a stone’s throw away. Dipper sensed this was a different kind of forest entirely. The chances of running into a cryptid were almost certainly lower for one thing.

A muttered cursing from behind the front door was followed by the sound of locks being unhinged. A single heft and the door was pulled away, leaving a grinning Mabel, sunglasses perched on her forehead, leaning against the frame affecting a cool air. “Yo yo yo, welcome.” She wrapped herself around Dipper in a side-hug, then gestured him inside. “Come on, park your keister, bro. I bet you’re tired from the drive. It’s great to see you.”

All his concerns from before melted away. The divide he feared between them was nothing but a bout of undue anxiety. Mabel was happy to see him, as she’d always be from now on. “Great to see you too,” he said with a grin. “So, this is where you’ve been chilling out for the last few weeks.” 

Mabel had a habit of moving around a lot, never in one place for long. Often his attempts to contact her would fail, his letters arriving after she’s already left or spotty connections keeping them apart. The only constant was that she’d always call from someplace else than before, some new exotic locale where she’d parked her special brand of troublemaking.

In the past he’d resented her for this. In his eyes she was just running away from any kind of responsibility. Now he sympathised more with that wanderlust. To simply take what you could carry and head off into the unknown.

Mabel’s newest abode was hard to make out with the sunlight glinting through the wide bay windows. Squinting, he saw the interior of the rustic cabin. It was airy, with an open sitting area dotted with pillows and comfy sofas abutting a kitchen with cabinets of painted wood.

Donning her sunglasses, Mabel grabbed a bottle of beer from the counter took a deep swill, before guiding Dipper out onto the balcony. “This is the life, eh.”

He sat down on a chair overlooking the sea and slowly nodded. “Yeah, I could get used to this. Not quite got the same…” He drifted off, an expression of warm remembrance on his face.

“Same what?” Mabel asked.

“Not got that same _thrill_ as home though, does it.”

Mabel leant over the balcony as memories of the hundreds of adventures they’d gone on as a pair or trio with Pacifica. Her smile grew into a smirk, something Dipper didn’t fail to notice. “Well… you might be surprised.” As he raised an eyebrow, Mabel’s tone grew serious. “Let’s talk.”

* * *

With the sun now long set over the distant horizon and reheated pizza scattered around the living room, Mabel spread a bunch of papers across her kitchen table. She tapped a basic map of the coastline. “Nearest town, that’s Sapphire Bay. About 20 minutes on foot. They got beaches, boardwalk, carnival stuff. Perfect place for a getaway.”

“Is that the reason you brought me out here?” Dipper crossed his arms sceptically. “To unwind?”

“Hold your horses, I’m getting to the important stuff.” Mabel sifted through the documents and grabbed a pamphlet of local hotspots. “Most tourists that pass through are college kids, visiting for their spring breaks or whatever.” 

“Lemme guess, lots of young adults getting wasted and partying all day and night.” 

“Not all of us go on boring walking vacations like you.” Then she shrugged. “But yeah, you’re not far off.” With her black crop-top and colourful tattoos Mabel looked every bit the part of a small-town rebel, sticking it to the man and living life to the full on the beach. She fit in perfectly.

“That why you’re here then? A rest.”

“You could put it like that.” Mabel lent back in her beanbag, oddly pensive. “Needed a break from all the travelling. Last year was totally intense, as you well know. And with Zera off in space with that budding phase of her lifecycle, I thought I’d take some Mabel time to myself.”

Dipper detected a hint of reticence. Mabel’s relationships had never been easy to define – let alone when her partner wasn’t even from Earth. “You two still all good?” he asked gingerly.

“Oh yeah yeah, fine. This is something she’s gotta do, I understand. She’ll be back in a month or two.” Mabel sipped from another bottle of beer. “Anyway, how about you? Pacifica really chose to stay home watching the kids? Don’t tell me she’s gone all maternal at last?”

Dipper snorted with laughter. “You really think? No, she just doesn’t care to drive all this way on a whim.”

“Ha, that sounds like her. When you get home tell her she missed out on all the fun.”

“You bet. I gotta say, moving back to the Falls permanently was a great idea.” It had been a hectic few months deciding to finally return to the West Coast. The work of moving had left little time for their traditional Mystery Hunts or journal time. But Dipper wouldn’t have given up one second with his new family for the world. “Pacifica’s certainly got her hands full. Merrise is struggling a little; still a new environment for her and all. Plus someone’s gotta look after the baby.” He set down his own drink and bent over the table. “Anyway, enough about me. I know you; we could be stuck on gossip all evening. Tell me why you need my help.”

Mabel leant back, melting into the beanbag, puffing out her cheeks. She was deep in thought about where to start. Stretching up out of her cocoon, she grabbed a single sheet off the pile strewn on the table.

“I got here a few weeks ago. My last protest kinda went south, you know, the one in Paris, with the unions, and I wanted somewhere to crash.” Dipper nodded. He remembered seeing his sister’s face on a news channel, though thankfully only in passing as part of a crowd. Mabel was getting better at keeping a low profile these days. To minimise the consequences should her actions suffer repercussions that might affect him and his family. Still utterly devoted to the cause, but mindful of getting others caught in the crossfire.

Mabel turned the sheet around to show Dipper. There was a grainy shot of a young man with name and identifying features beside it. Traditional chiselled features of your average jock visiting the beach. At the top of the poster was a single word, underlined in red:

Missing.

Dipper felt a pit of dread in his stomach. He knew where this was going.

“Spotted this on the boardwalk,” Mabel continued. At first I thought it was nothing. One lost kid, what can you do? Then more people started disappearing. Almost all the cases have been tourists. Like I said, lots of college kids passing through, having fun… and never going home.”

“And you think there’s something linking them?” Dipper cautiously asked.

“Lotsa kids vanishing, all recently, within the last few months as far as I can reckon. Normally I wouldn’t call you for something like this, but there’s something else on top.”

Her next document was a blurry polaroid. Dipper could make out crashing waves and a bulky shape in the water, but it was vague enough that it could have been anything, a boat, driftwood. Seemed to him that most cryptids were naturally camera shy.

Mabel was deadly serious however, and he was there right along with her. “You took this?” he asked, but she shook her head.

“Local paper. Last Tuesday. And there’s more.” She rifled around for a list of witness testimonies, but Dipper held up a hand.

“I get it. This is more than a simple missing persons case.”

Dipper pondered the facts. There was something oddly haunting about unsolved mysteries quite like this. Mundane in some ways, but the thought of people just disappearing off the map without a trace still gnawed at the back of his mind. Maybe, he considered, it was parenthood. Being responsible for his own kids, imagining a myriad of potential fates for these lost youths got to him.

Mabel tossed the paper down, her face contorting into an angry scowl. “I’ve tried figuring out what’s going on, but nobody likes talking about it. The cops certainly don’t care; to them it’s just a bunch of out-of-towners getting overwhelmed partying. ‘Can’t handle the lifestyle’, that’s what they say, before dropping all investigations.”

From her tone, Dipper could guess this was a common point of contention for her. She’d probably attended a number of riots protesting against the very corruption she was outlining right now. As a whole, she preferred relying on herself to sort things out.

“I know it’s not some grand conspiracy to solve or anything big like that. But it’s real, Dipper, and it’s happening to innocent people.”

Immediately he assuaged her doubts. “You don’t have to worry. I know how important this is. Besides, after everything we’ve been through in our lives we deserve to take it small-scale. Do some practical good.”

Mabel’s resulting grin was infectious. The spark of adventure was already spreading. “Right then!” She stood up decisively and tucked away her messy pile of collected evidence. “Tomorrow morning we can head into town. I’m already friends with a bunch of the locals, we can work on getting some pointers.”

“I’m sure once the Mystery Twins set up in town we’ll have this cracked in no time.”

“Cheers to that.” They clinked their bottles together, ready to solve this thing as soon as the sun rose.


	2. Filling in the Map

Awakening with the morning dawn, Dipper was up and ready to head into Sapphire Bay to begin their investigation. What he wasn’t ready for was Mabel’s mode of transportation.

Now his arms were clamped around his sister’s waist as they hurtled along the beachside road on her motorbike. Mabel took the next corner at a break-neck speed, barely avoiding clipping the wing mirror of a passing truck heading in the opposite direction. Dipper gave an audible yelp and squeezed Mabel’s waist even tighter. She gave a giddy laugh in response, throwing her head back and embracing the wind rushing by.

To add to the indignity Mabel only had one spare bike helmet. And it was bright pink.

Dipper tried to hide his shame as they entered the town proper. Though it was still early, there was a buzz of activity, with storefronts opening and packs of hungover teens stumbling around like zombies from the night before.

Mabel suddenly pulled hard on the brakes, causing the bike to screech to a stop. Head still shaking from the unexpected jolt, Dipper got off as fast as he could and bent over double.

Mabel took off her helmet and brushed her close-cropped hair out of her face, then smirked. “Sorry bro, forgot this was your first time on a bike.”

“You did not. The way you were cutting those bends…” He shook his head. He should’ve expected a bit of Mabel’s usual flair for the exhilarating. Noticing Mabel had dismounted the bike, he was glad to be rid of his own gaudy helmet. “Why have we stopped?”

Bent over the side of the bike, Mabel spoke without turning to him. “I think some of the joints inside are getting a bit stiff. Need some oil.” She revved the engine as if to make the point, but Dipper had no ear for that kind of thing. “Come on, I know a place.”

Wheeling the bike beside her, she led Dipper down the high street. He could already see the appeal of living somewhere like this. All the open spaces of cliffside roads and every kind of convenience here in town. It felt alive, pulsing with energy even at this early hour. 

He was also trying to notice anything untoward that might give more clues to solving the disappearances, but outwardly Sapphire Bay was just your average prime vacation spot. If it _was_ something weird causing all the trouble then it wouldn’t be out in the open anyway.

He got his journal out from his jacket and started writing down these first impressions, in case something jumped out at him later.

“What Journal are you onto now?” Mabel asked, peering over to get a look.

“Number 9.” He held up the cover of golden lines and inky blackness, emblazoned with the number and displaying the Big Dipper; the design Mabel had created that he proudly carried everywhere.

“Man, you’ve been filling those things fast. I swear you were still on book 7 last I heard.”

“That’s what living in the weirdest place on Earth is like.” He shrugged and tucked the book under one arm.

“All the best intel will come from talking to the locals, trust me. You’re gonna love meeting my friends.” Arriving halfway down the street at an open garage, Mabel kicked out her bike stand and called out. “Hey, Toni! Need another check-up on my baby.”

Wrinkling his nose from the smell of hot metal and gasoline, Dipper couldn’t see who she was talking to at first, before spying a pair of legs poking out from the undercarriage of a car chassis. Mabel dumped her brown leather jacket and gloves on the bike, then hooked her foot on a roller. Out from under the car slid a girl with a bright streak of blue hair and a face covered in motor oil.

Initially startled, she grinned at the sight of Mabel. “May! How’s it been?” She set down her tools and sat up. “Don’t tell me: you need another oil change.”

“You know it, Toni.” She turned to Dipper, glad to introduce him. “My girl here is the best fixer-upper in Sapphire Bay, she can make any bike purr like a newborn kitten.” 

Mabel pushed the bike over, but the mechanic held up a hand. “It’s gonna have to wait. I’m already running behind today, and I have to head off for a few hours.”

“Oh, come on,” Mabel pleaded. “You know how much I love this bike.” She ran a hand lovingly over the contours of the vehicle. “The rush of the wind, the smooth handling, the power of that engine beneath my legs. Like a wild animal, rawr.”

“Well sorry.” Toni picked up a wrench. “If you want you can leave it here and I might be able to patch it up by this evening.” She was about to slide back under the chassis when she noticed Dipper for the first time. He’d been hanging back, watching the discussion disinterestedly. Bikes and cars and noisy repair work weren’t really his thing.

But the way the girl’s face transformed when she saw him sent an incredibly strange feeling through him. She pursed her lips in a curt smile and narrowed her eyebrows, so her gaze pierced into him. “Who’s this strapping newcomer?”

“Uh, excuse me?” he replied, put off by her tone. “I’m, uh, Dipper.” She slid over on the roller and pressed against him.

“Well _Dipper_ , I can show you round a chassis anytime you like. I like a man who’s smart and tough.” Toni ran a finger over the binding of his journal, then appreciatively squeezed one of his arms. Recoiling slightly, he tensed up, totally unprepared for what exactly what was going on.

Was she _flirting_ with him?

“This is just my brother,” Mabel said, not picking up on the obvious moves Toni was making towards him. “He’s visiting from out of state,”

“He staying for long?” Toni asked without taking her eyes of Dipper. He was a deer in the headlights, unable to articulate any kind of response.

“A little while. But probably only a week or two at most. He’s gotta get back to his family, he’s a new daddy!” Mabel said in a voice sickeningly sweet enough to puncture whatever swagger Dipper might have thought he was showing off. Toni immediately pulled away too, since it was clear he was no longer available.

Pouting, she laid back down on the roller. Mabel’s foot reached out to stop her ghosting them under the car again. “Forget all that. I was wondering if you could help us out.” She made eye contact with her brother then looked down at her friend. “See, Toni here has intel. Me and my brother are looking into that case I told you about. All those missing kids. You said you’d seen something, right?”

“Sure, I saw _something_. But I don’t know what you’re expecting me to say. It was dark, it was big. I thought it was a deer or elk at first, but it didn’t run.”

Dipper excitedly opened his journal to document her words. but was saddened when she didn’t continue. “That’s it? That’s all you can tell us?” It was barely a fragment of a lead to go on. He tried to gain something useful at least. “Where did you see whatever it was?”

“Uh, out in the woods, I think. I was pretty drunk that night. There’s an site me and my friends use, old bonfire and a bunch of lawn chairs. Great place to get hammered.”

Dipper noted it all down. No matter how sketchy the description it was still a possible lead to base an investigation on.

“Seriously, that’s all you can tell us?” Though Dipper was satisfied with what they’d learnt, Mabel still wanted more. “Couldn’t you show us the place in person? Or try and remember more?”

“I’ve got stuff to do. All day.” Toni checked over the underside of the car one last time, before giving up and wiping her hands on a rag. “First I’ve gotta get new parts from the store, then I need actually fix this thing. Then maybe I can look at your bike too.”

“Can’t you get someone to cover you while you help us? You could call Merc? Or Sam? Even little Frankie from the boardwalk, she could-”

“Sorry, but I’ve got errands to run after that as well.” She gathered her things, gazing one last time admiringly at Dipper and once again making him feel all kinds of awkward. Then she locked eyes coldly with Mabel. “Look, if you really need me, then after work I’ll be at the farmer’s market.”

“What do you need to get there?” Mabel incredulously asked. Toni just turned around and flipped the bird at her. “See, isn’t she great.”

“Your friends are weird,” Dipper stated in a deadpan.

“That includes you and Pacifica, you know?”

He shrugged. “Ah, beggars can’t be choosers. Do you really I think I look stronger?” He experimentally tapped his own arm muscles, slightly unsure if he was being made fun of or it had been a genuine compliment.

“I guess, yeah. All that travelling and stuff has made you the tiniest bit buff for the first time in your life. Can’t compare to these babies though.” Mabel flexed her arms and pursed her lips, showing off her guns in the most obnoxious way possible.

“Alright, alright, I get the picture. You’re the brawn, I’m the brain,” he teased. “Now, about cracking this case. You said you had more friends that could help?”

* * *

Still mulling over the curious way Toni had acted towards him, Dipper let Mabel guide him on autopilot through the town. In all his life he’d never considered himself much of a catch. In high school he’d been one of the nerds – not hated by any stretch of the imagination but hardly an object of desire. That was more Mabel’s territory, she could schmooze with the popular crowd effortlessly.

Of course, Pacifica loved him and that was all he needed. Even then he’d always thought she saw him more for his quick-wittedness, or as an escape from home life. Not, to put it lightly, a piece of meat to be ogled.

“That the first time you’ve ever had someone else flirt with you?” Mabel piped up, keenly aware of his introspection.

“You noticed,” he huffed. “Suppose it was kinda obvious; you don’t need to have Paz’s observational skills to see that.”

“You should take it as a good thing bro, Toni thought you looked nice, it was a compliment.”

“I guess.” He hoped that would be the end of the conversation and tried to observe the town again.

Mabel quickly broke the silence. “Come on, you can’t handle it?”

“I’m a qualified Astrophysicist,” he said proudly, before mumbling, “Who doesn’t like making small talk, ok.”

“My friends aren’t gonna bite,” she said, almost giggling at the idea of her brother being so knocked off his guard “Besides, you were fine asking Toni about the mystery stuff.”

“That’s work, it’s different.”

“Well trust me, not everyone’s gonna want to chat you up. You’ll be fine. I mean, the last thing we solved was a murder mystery on an alien planet. I’m sure you can handle a little small-town intrigue.”

“After your last friend I’m not so sure. Come on, we’re wasting time.” He picked up his pace and Mabel was glad to see the spring back in his step. They passed more tourist spots in town. The main beaches were all packed with families and visiting groups of teens and students, glad of a break in the sun.

Down at the long boardwalk it was quieter. This was the prime of the day and most tourists wanted to be out on the sand or swimming in the sea. The only people milling about were occasional food vendors and older people reclining on sun loungers away from the busy crowds.

There was also a small cluster of people roughly around their age, three of them sitting on a bench in the empty thoroughfare. They didn’t fit into the other neat groups. They weren’t retirees or visitors to the town. They were locals. To them the attractions of Sapphire Bay had long since become routine. So they were hanging out here, away from the hotspots.

Dipper could guess that these were Mabel’s contacts, the friends she’d made since moving here.

“Tarik! How’s it hanging my man?” Mabel approached one of them, sat at the edge of the bench away from the others, who were loudly talking to each other.

The scrawny guy seemed annoyed but smiled when he saw Mabel. “Hey, look who’s here, life of the party.” His mood dropped in an instant. “You finished listening to my mixtape yet?”

Mabel raised her hands to try and soften him. “Just gimme a day or two more, I’ll have it all listened to by then, promise. This is my brother,” she said pointing at Dipper.

Tarik softened again, flipping back to positive like a light switch. He reached out and shook Dipper’s hand. “Hey man, always a pleasure to meet someone new. We get a lot of folks passing through.”

Dipper already felt more comfortable around him than Toni. He had an easy-going vibe, laid back and here to unwind. “Nice to meet you too. Has my sister been her usual preachy self?”

“Preachy?” Mabel blurted out.

“Oh, yeah, all the time,” Tarik carried on. “Keeps trying to give me bumper stickers with slogans on or making me buy alternative brand cereal, junk like that.”

“Sounds like her,” Dipper said. Much as Mabel pouted in that moment, one couldn’t deny he knew her well. Though she only meant the best of intentions, her way of going about them was more like a bull in a china shop. It was messy and unsubtle, but passionate nonetheless. “Back to business. I’m here about the-“

“The mystery stuff, I know. May keeps chewing my ear off about it. So what are you? Some big-time conspiracy nut?”

Dipper’s jaw dropped open and Mabel chuckled. Tarik had figured his role in proceedings as fast he’d descried Mabel’s.

“Tarik’s a surf instructor,” Mabel explained. “He doesn’t get around town much, but he does speak to a lot of people who visit. He met one of the missing kids, you know, before they were missing.”

“That’s right,” he nodded, and Dipper once again got out his journal in preparation. “Blonde guy, preppy type. Name was Ethan, or Eric, or something pretentious like that. But he never turned up to his third lesson. Vanished like that, no-one knew where he went.”

“Now his poster’s up with the others,” Mabel stated. “Parents or friends put it up, I dunno”

“So nobody knows if he’s alive or dead,” Dipper finished, closing his journal again. “Grim stuff, I know. But that’s why I’m here, to sort all this out.”

“Is that so?” Tarik asked with a raised eyebrow. “Maybe you can talk some sense into these two then?”

Dipper panned over to the others before doing a double-take. An intimidating mass of a man lounged on the bench, bulging muscles rivalling Mabel’s own barely contained by a white t-shirt. There wasn’t a single head of hair on his entire body that Dipper could see. Quite a contrast from the girl sitting next to him on top of the bench, whose curly locks flowed down to cover half of her dark brown face.

It seemed the girl was in the midst of a heated debate with muscle man. “You are totally accusing me!”

“So own up and give me back my maps, I know you took them!”

“I did not.”

“Hey hey, what’s going on here?” Mabel tried to push herself between the two, hoping to deescalate whatever petty argument had erupted. She did so hate to see her friends fight. “Merc, Sam, calm down.”

Dipper felt an instinctive flinch at the gruff voice of the man named Merc. “She’s a thief, that’s what’s going on.”

Sam flicked some of her hair and looked away. “It’s a witchhunt, he’s being totally judgemental. I’ve not been anywhere near your house. I was working all night.”

“I know it was you, you’re the only one in this town nerdy enough to care.”

“No no no, we’re not doing this.” Mabel started yelling at Merc, laying into him for daring to accuse Sam, before letting off a string of profanities in Spanish that Dipper could barely keep up with. Merc rolled his eyes and walked away, knowing he couldn’t argue against Mabel’s barrage.

“What just happened?” Dipper asked, watching Merc storm off, unsure of the personal dynamics and how to react. Tarik similarly looked to him and lazily shrugged.

“Merc is just being an asshole,” Mabel said. “He thought poor Sam here had stolen something from him. Talk about projection much.”

“Yeah,” Sam said, “the amount of times I’ve caught him out with late fees from the library is insane.” She spotted Dipper and smiled, clearly trying to put the debate behind her. “Hi, you must be May’s brother.”

“How’d you know? Wait, let me guess, it’s that we look really similar, am I right?” He was glad to hear Sam laughing in response. The mood could do with lightening after Merc’s outbursts.

“May, you said something the other day about trying to fix things in the Bay?” Mabel nodded and Sam got up off the bench. “I’ve got something to show you.”

Intrigued, the siblings left Tarik, who again glared at Mabel, and headed at Sam’s direction further down the boardwalk. Out here they were over the water, waves constantly crashing against the wooden pier. Feeling more confident after his shaky morning, Dipper walked with a determined stride. The more people they spoke to the better understanding he’d have of the case. Soon they could begin to properly investigate the leads and hopefully resolve it all in no time.

Detecting his better mood, Mabel opened her arms wide as they walked. “This is the place to be, Dipper. Out here by the water, sun shining, people happy. Maybe after this we should take it easy, go for a swim or something before we start Mystery Hunting.”

“Yeah, I could go for that,” he said, admiring the crystal blue water all around.

Sam too seemed to appreciate it, all traces of the argument earlier forgotten. “Reminds me of my brother, he used to love the water.“

“I didn’t know you had a brother too!” Mabel excitedly said. “We should share embarrassing kid stories sometime.”

“Hmm, maybe.” Sam seemed to trail off, and Dipper detected an odd hint of melancholy in her voice.

“Something the matter?” he asked.

“Oh, it’s nothing. Haven’t seen him in a while, that’s all. Here we are.” Dipper was happy to leave Sam’s statements behind, fine without getting too tangled in all of Mabel’s personal relationships and they stopped by a noticeboard at the end of the pier. “Thought you ought to see this.”

The twins looked up at the board and their hearts started to sink. Plastered to the wood were dozens upon dozens of missing people fliers, flapping in the sea breeze.

“Oh my god,” Dipper said, grabbing a poster at random off the board. “I had no idea the problem was this widespread.” He tried to scan over the posters, looking for dates. It might help to know when the earliest disappearances had started.

Mabel was standing stock still beside him, silently taking in the sight. Suddenly she spoke, quietly. “Some of these are new.” She pointed to one dated only two days prior. “It’s still happening, right under my nose!” This time she was angry, burning with a fury Dipper had barely witnessed in her before.

“Woah, hey, it’s ok Mabel.”

“No it’s not! Look at this! All these people just vanished. All my life I’ve tried to fight injustice, but this is staring me in the face, mocking me. What good is all that work if this sort of thing goes on regardless?”

Sam tried to calm her down. “Hey, I’m sorry, I didn’t mean-“

“It’s ok Sam,” Dipper said, lightly resting a hand on her shoulder. “I understand the scale of this problem now at least.”

She raised a small smile. “I just wanna help too. Make Sapphire Bay safe again. May, you ok now?”

Mabel had rested her head against the board, enveloping herself in the posters. She didn’t say anything at first, before abruptly speaking. “Thank you Sam. It’s good to know someone in this town gives a damn. Not many people do, and most of the ones that care don’t have the power to do anything.”

“Mabel Pines: giving power to the powerless. That could be your motto.” Dipper meant it half-jokingly but had to admit he was being swayed by his sister’s obvious commitment to this case. “Alright, where do we go next? We can stop this. We can make sure no-one else goes missing.”

“Yeah, that’s what we’re gonna do.” Mabel wiped her face indignantly, not wanting to seem vulnerable in front of Sam. “But as for leads, I’m not sure. I’ve got other contacts, but we’ve spoken to all my go-tos. I could try a spell. I got that tome from Bo for our birthday-“

“Maybe lay off the magic for now,” Dipper said, mindful of an uninitiated person like Sam nearby. “At least until we know what we’re dealing with. If it’s not something out of the ordinary we don’t want to draw too much attention to ourselves.”

“Not like it would be the first time. Government’s not out for my head and we’re not being hunted though, so I guess I should count my blessings.”

Dipper brought out his journal again, poring over the scant notes he’d made that day. “This place isn’t a weirdness magnet like Gravity Falls. We shouldn’t expect to find some easy paper trail or a history of sightings. It seems like more of a drive-by mystery. Something recent, something new that’s changed.”

“I think we should focus on learning more about the sightings. Like what Toni saw.”

Sam spoke up. “I saw something like that.” Both twins turned to her, eager to hear more. “It was inland, near the suburbs. Didn’t get a good look but it weren’t no animal I’ve ever seen before.”

The twins stared into each other’s eyes, communicating non-verbally what their next move should be. “Split up,” they both said at once.

“I’ll take the forests, look for Toni’s sighting.” Dipper found the relevant text in his journal to compare. “You take the town, you know it better.”

“Roger, it makes sense.” Mabel pulled out her tourist guide to Sapphire Bay, handing it to Sam to show her where she’d seen the creature. “I’ll use my tracking skills; anything out of place and I’ll sniff it out.”

“Right, we’ll meet back when it’s dark. Thanks Sam.” The girl nodded, amazed by how fast they’d come to a plan of action. Dipper turned back to his sister. “Betcha ten of your favourite presidents I’ll find a creature first.”

“Oh, you’re on mister.” Mabel smirked and fistbumped him. “Last one to solve the mystery is a rotten egg!”


	3. Uncharted Territory

At the edge of Sapphire Bay, far from the coast, Mabel reached a collection of houses ending in a semi-circle. Just over the back gardens of each house could be seen the forest, the darkness within pushed back by a dozen flickering bug zappers.

This was the place where Sam had seen… well, that was what she was here to find out. While Dipper hugged the beachward routes, she’d headed inland. Sam didn’t live here, but a lot of the kids in town knew this place. The graffiti daubed all about made that clear. 

With time to kill, she reached into her pack and started painting over a particularly mean swear word she took offence too. With a few sprays from her can it was beautified, a rainbow of colours and butterflies. If she was going to fix the ills of this town she might as well start with the basics.

Heading back to her mission of tracking down whatever might be lurking nearby, she began by doing a sweep of the street with her flashlight, before probing deeper in the shadowy woods. Shoving bushed and twigs out her way, she trampled her way into the undergrowth as she had on so many adventures with Pacifica and Dipper by her side. Maybe once all this was over she could pay a visit to the Falls, spend some time with her friends and family.

For now, she was happy to spend her nights in pursuit of whatever was plaguing this perfectly ordinary little town. Sapphire Bay had been a good home to her these past weeks, with lazy days spent reclining on the sand and wild nights at the club with her friends. It was an easy place to live, free from the more nagging concerns plaguing the wider world.

Someday she’d have to get back to that work, but in the present her first sweep of the neighbourhood had pulled up nothing. While making her way around again more carefully, she thought she’d struck gold. Near a communal area where the street’s garbage bins were located, she heard a rustling sound from behind one of the dumpsters, like a raccoon gorging on what scraps it could find.

If it did turn out to just be a harmless little scavenger, then no trouble. But if this was finally a chance for her to confirm the rumours and find something concrete, well, she couldn’t miss it. Creeping slowly around the chain-link fence, she saw a small hole underneath. Too small for a human, but for something else…

She mentally prepared herself, tensing her muscles and getting in a battle-ready stance. Counting down from five in her mind, she leapt around the corner to confront the intruder. “Aha!”

Mabel dropped her fists. Far from an innocent woodland creature, she was staring at one of the most utterly bizarre things she’d ever seen – and that was saying something.

A single foot, and atop a minute stump that blended both ankle and neck sat an almost human head. The whole tiny body was covered in dark bristly hairs, with the greasy skin of a middle-aged man who didn’t often wash. Fittingly, she supposed, it was about a foot and a half tall, just barely reaching the height of her knee.

“Wut.” Mabel couldn’t come up with the words to adequately express herself. The creature, ignorant of her bafflement, started mumbling to itself, a babble of nonsense like baby talk, making things even stranger. She’d seen many odd sights in her nearly 30 years – giant talking bees, immortal insects, even sentient French golf balls – but this was so far up the weird-o-meter that she had to take some time just to process it.

Then the creature finally noticed her staring. It gave a piercing discordant scream, like scratching something along a piano string, before hopping away. It was an ungainly process, forcing its single large muscle to lift the entire body in a leap forward. But it was moving fast, like a spooked rabbit fleeing from a predator.

Scrambling to action at last, Mabel shot off in chase. Each bound of the creature gained more ground between them. She tried firing off a line from her grapple gauntlet, but the foot’s low profile meant she went too high.

She was going to lose this thing. It was going to escape and pogo-stick itself back into whatever festering hole it had come from, and she’d lose her only lead so far. She owed it to all the people who’d lost loved ones to figure out what this gross little foot had to do with anything.

The creature rounded a corner, heading into the alley between two houses. Mabel skittered round, nearly failing to change direction in time. The alley ahead of her was empty though. The path beyond was fully lit; it led round to the main street again. She dropped to a crouch, running her hand along the ground, searching for tracks.

It couldn’t have just evaporated into the air. Well, maybe it could – she’d learnt not to rule out anything – but right now she had to work with what she had. She felt the deep indent of its footprint, then moved on to the next. It curved slightly. Right on the ground there was a window, leading into the basement of the house of the left. Could it have gone down there?

The creature didn’t seem like it had the dexterity to prise the window open. If it had run in there instinctively then perhaps this was some kind of lair. The source of all this mystery.

She pressed her hands to the glass, trying to jimmy the window open. Through remarkable ease she was able to slide it open, without resistance. Pressing herself flat on the ground, she could just fit in the gap. Feet first, she wiggled into the basement and hopped silently onto the stone floor.

Step one of the infiltration complete, she quietly crouched forward, stepping lightly. It was dark down here away from the street. All she could make out were several tall shapes against the gloom, reaching up to the roof. Support pillars? There was also an odd aroma in the air, a tangy whiff that made her nose curl.

While her other senses were confused, she could still hear the light padding of the creature’s single foot. Coiling herself, she pounced at the small freak of nature. Unfortunately, it chose the exact same moment to leap at her, launching itself into the space she’d been occupying before. Seeing an opening, it started hopping like mad away.

Forgetting any hope of stealth, Mabel fumbled after the thing, knocking into a waist high bench. She clumsily fell over, bringing the contents of the bench down on top of her. What felt like soil and leaves covered her.

The foot jumped right back out the open window, pausing only to stick out its tongue at her before vanishing into the night.

“Ah, damn it.” So much for catching her little cryptid. She got up, brushing the leaves that had fallen on her. She picked one up and gave it a quick sniff. “Wait, I know this smell.” Her eyes had adjusted and now she could see that the tall objects surrounding her were actually bushy plants with broad spiky leaves. It wasn’t her first time seeing plants like this. She’d even tried her hand at growing her own once and was also intimately familiar with the effects of smoking it. “Oh dear.”

Far from some creepy dungeon at the heart of the plot, Mabel had stumbled right into someone’s unofficial weed den. And she hadn’t been subtle about it.

The hurried sound of footsteps from upstairs put her in a panic. Before she had time to climb out the window, a door flew open and she was blinded by the beam of a flashlight. “Uh oh.”

* * *

Dipper knew that perhaps the most important skill to have when hunting for cryptids was patience. One could hardly expect to coax out the rarest creatures known to man easily. It requires careful laying of bait and traps, tracking movements over potentially huge areas and then lying in hope that you’ve picked the right spot. All to finally be rewarded with but a tantalising glimpse of something out of the ordinary.

However, his own patience was being severely tried right now. After finding the campfire Toni had described – now a burnt-out pile of ash surrounded by empty beer cans and bent lawn chairs – he’d started making guesses to which direction she must have ambled in to stumble onto whatever she’d seen.

There were sturdy pine trees stretching away in every direction but one: towards the ocean. There the trees ran almost right up to the sea, with only a small strip of sand acting as a buffer between the two.

Postulating that in a beach town there was a likely possibility that their wayward cryptid might be aquatic, he set out a small pile of food, berries and a snack bar he had on him, to lure it out. His bait was halfway between the camp and the sea just in case his hypothesis turned out to be incorrect.

By now he’d been waiting nearly two hours with zero signs of movement. Thanks to a clear moon he had fairly good lines of sight, but still nothing. Barely even any bird calls or squirrels. As if something was scaring them away, some higher predator. That was what gave him a glimmer of hope, that maybe that was the reason he wasn’t finding anything.

At least he had something to read to pass the time. It was actually one of Pacifica’s own books. After abandoning her previous career as an architect and her first forays into the author/illustrator role she found it came naturally. Since most of her work was semi-autobiographical she basically got to indulge in one of her favourite pastimes: rampant gossip.

The book Dipper was currently reading was a tell-all exposé into the business world she’d grown up in. Largely pretty dry stuff to him, but he got a chuckle out of every time she disparaged her parents or some other rich businessman in the text.

His mind drifting as his eyes glided over the words, he pondered his current situation, hundreds of miles away from his wife and children, huddled in the darkness in tentative wait. It was hardly the first time he’d spent a night alone out in the woods, but he missed his new family more keenly than before.

Perhaps Mabel felt the same? He had been surprised to receive such a direct summons from her for once. Although she’d clearly made friends here in Sapphire Bay, he couldn’t help but notice a slight separation from the rest of the town. She’d always had similar anxieties about being alone. Right now without her family, her girlfriend, or even her pet snake for comfort, it was no wonder she’d called in a familiar face to help out.

Movement caught his attention. The rhythmic certainty of the waves, crashing against the nearby shore, was interrupted. Water struck the land in a new melody. Dipper returned his focus to what was in front of him and snuck closer to get a better look at what was causing the disturbance. Out in the water he made out a dark patch, moving through the water slowly towards land.

An enormous grin broke out on his face. Mabel had been right. There was something happening in this town. Something weird and incredible.

This was what he craved most about Mystery Hunting. That instant when he finally caught a glimpse of the unknown. That incredible sense of wonder that had never diminished no matter how many countless phenomena he’d uncovered. He’d been able to share that experience with Pacifica over the years, to the point where she too craved the adrenaline rush of the novel and fresh. He gave anything to savour those moments.

Yet as the creature approached, the sense of wonder started to turn into something quite the opposite. The bulk of it, which had before seemed about the size of a dolphin or maybe a manatee, now revealed itself as much larger, practically a small whale. Actually, scratch the small, he thought, as the dark shape grew nearer and nearer.

Two jets of spray burst free from below. Dipper stepped back but tripped over in his panic. The inexorable shape sped up, racing towards him. A part of the creature’s bulk rose out of the ocean, with twin smokestacks belching water into the air.

The churning sea erupted, spraying him with sand and water. He crawled backwards with his elbows, sand digging into his rear but desperate to back away. Finally the whole creature emerged. Despite the utter terror Dipper felt, he still couldn’t resist grinning like a madman. “Oh, you are beautiful.”

The aquatic monster roared and Dipper quickly remembered his survival instincts. First catalogue; figure out what you’re up against. That was easy. The monster was forcing its large bulk onto land, with two great flippers dragging the body from beneath. A lipless mouth crammed with teeth was heading ever closer to devour him.

He finally managed to get on his feet and ran away, trying to get a full view of the beast. It had an ugly face, something only a marine biologist could love, spawned from the darkest depths. The jaw was beset on either side by whiskery cheeks, and on top, two blowholes on stalks sticking out of the head. Occasionally spurts of water would fly out, further drenching him with salty spray.

It was unique, a totally unrecorded marine specimen. And he was about to become its lunch if he didn’t react fast. Searching for any way to fight off the beast, he tossed Paz’s book at the hungry jaws. The beast merely chewed it up in a flurry of wet paper.

Barely slowed down, it continued its relentless march onto land. One advantage Dipper had over the beast was that it was slow and cumbersome out of the water. It might catch him eventually, but he could outrun it. At least, in theory. The jaws lunged at him and he dived to the sand. All the creature ended up doing was tearing off a scrap of his red hoodie. He’d prefer it that was the only red part of him ripped off; he didn’t relish the idea of his feeble flesh being fed to that meat grinder.

The trees. They were his only option. The creature was massive, it would never fit between the broad trunks. Clambering up the slope off of the sand, he broke into a sprint back into the forest. Passing the first trees he gave a sigh of relief.

Undaunted, the wet mass pushed furiously against the wall of foliage. The trunks started to buckle and tear out of the ground. At a safe distance now, Dipper started frantically writing notes in his journal and speaking aloud to himself. “Incredible, the sheer force! No wonder people have gone missing if things like you are swimming about in the same waters.”

The creature beat itself against the trees again, but it was useless. It wouldn’t be able to follow Dipper any longer. It gave an angry roar and started turning to re-submerge itself.

“Going so soon? But we only just got acquainted.” As the creature turned Dipper made more observational notes, scribbling as fast as he could to describe every detail. He had a perfect view and endless time to make sure his record was accurate.

But then something happened that confused him. Rather than just slipping back into the sea and swimming away, the creature began to writhe in uncomfortable agony. Dipper tried to see what was wrong. It might have crawled over a sharp branch and hurt itself. Suddenly a golden light enveloped the monster, blinding Dipper and completely obscuring his view.

When the light receded, the creature was gone. The only trace it was ever there were the deep indentation in the sand and several nearly uprooted trees. This wasn’t a simple case of a sea monster grabbing people in the night. Something far more complex was affecting Sapphire Bay.

Dipper needed to know more about this creature. With no more leads to pursue there was only one thing he could do. Good old-fashioned research.

* * *

“Who’s down there? I’m armed and I know how to use this thing!”

Squinting through the torchlight, Mabel saw her accuser, wearing a dressing gown, flashlight in one hand and golf club raised above her head in the other. She also made out blue hair and a face she recognised. “Toni?”

The mechanic’s eyes widened, and she switched off the blinding light. “May? What the hell are you doing in here?”

“You know, my best friend is a mean golfer, you two should play sometime. That’s probably not what you wanna hear right now, huh,” she said with a guilty chuckle. “So this is why you were acting all cagey earlier.”

“You broke into my stash!” Toni saw the minor chaos Mabel had wrought earlier, the scattered herbs and soil. She was not happy. “What is going on!?”

“I didn’t mean to break in, honestly!” Mabel had to dig herself out this hole fast. “I was investigating the missing people, you know. And I was chasing… something! Something strange! Like the thing you saw! And it came down here and I tried to catch it.”

“Really, you expect me to believe that?” Toni ran a hand over her face irritatedly and took another threatening step forward.

In response, Mabel turned on her most crowd-pleasing smile and put her hands together to beg. “I can make it up to you! I swear! I’ll pay you double for fixing my bike? Free guitar lessons? Anything!”

“You’re lucky I like you,” Toni said, though her frosty tone didn’t waver. “If you tell a single soul-“

“You have my word! I’d never narc on you like that, cross my heart.” She sidled up beside Toni. “In fact, you might have yourself a new a customer.”

Mabel winked, but Toni just sighed. “Whatever. I’m too tired for this shit. My mom better not find out about all this. Now I gotta pay to fix all the stuff you broke, buy new seeds and plant pots. Not to mention the hassle of calling in a locksmith for the window too. Thanks a lot, May.” Toni leant the golf club against the door and stomped back upstairs. “And don’t expect any discounts cause we’re friends.”

“Sorry,” Mabel called out, blushing bright red over the whole affair. Yet part of her was still focused on the mission. Though she’d lost her catch, there was still one question. She turned to look at the window. Below was a bent and broken metal bar. “I didn’t break that lock.” Neither did the strange single-footed creature, which had nowhere near the power to force it like that.

So what did?


	4. Horror Vacui

Following the trail of Dipper’s phone GPS, Mabel ended up at the town library. A single light was on inside. She pressed herself to the glass and smiled when she saw her brother illuminated inside, fast asleep beside a pile of books.

She opened the door but was surprised to see he wasn’t alone. Behind the main desk, Sam waved over to her. “Hello you. What are you doing here?”

“I work here,” Sam replied with a smile. “Someone’s gotta run this place. We _are_ technically a 24/7 establishment, don’tcha know.”

“Huh, neat. I bet Dipper was glad to see you.”

Sam looked over to his sleeping form and supressed a giggle. “I helped him look up some reference material. Lots of obscure stuff but I was happy to help. Don’t get many folks past this hour.”

Sam wiped her eyes with the back of a hand and yawned. Mabel saw bags under her eyes, and a sense of exhaustion behind the smile. “You look like you should get some rest.”

“Says the girl up just as late as I am.”

“Touché.”

Sam yawned again and did some busywork on her computer to try and stay awake. “I won’t ask what it is you two are really up to, but if it helps find those missing kids then that’s fine by me. Go on, check on your brother.”

“You look after yourself as well, ok?” Mabel said like a stern schoolteacher, before dashing over to Dipper. A nagging in her mind wanted to stay with Sam and make sure she was properly ok. Her haggard appearance felt like more than just late work. Maybe after fixing the bigger problem.

Seeing her brother, head resting on the table beside his research, reminded her of when they’d used to share a room in the Mystery Shack. Often she’d wake to find him sleeping, nose deep in some ancient tome, having spent the night expanding his knowledge.

She missed those innocent days whenn their bond had been strongest. It had only been natural that they’d grown more distant with age. As kids they’d been inseparable, but with the advent of new friends and careers and lifestyles their courses had ended up drifting apart. Too far apart, to the extent that they’d gone through that horrible five-year period of separation.

It was a relief for both their sakes that the bond had been mended lately. But still Mabel pined for simpler times when all she needed was her brother by her side to weather any storm.

All that said, she couldn’t resist a bit of mild sibling teasing. She grabbed both of Dipper’s shoulders and whispered in his ear. “Wakey wakey.”

Then she started violently shaking him, jolting him awake. “Huh? Wha? Pacifica, I’m awake, I’ll change the diapers today, don’t you worry.”

“Ew, gross.”

Dipper blinked a few times before seeing Mabel. “Oh, it’s you.” As his mind started to get into gear he remembered what he was supposed to be doing. “Great, you made it!” He arranged the books from his pile, open to specific pages all around Journal 9 in the centre.

“Woah, slow down there, partner, you can take your time.” Mabel herself had long since cultivated the uncanny ability to stay awake as long as she needed into the night. It was a skill required for both night-time mystery excursions, as well as last-minute all-nighters in school and college. Dipper was usually the more sober of the pair. “Sure you don’t need more rest?”

“Pfft, that was a power nap, I’m fine now. You’re never gonna believe what I ran into. Listen to this: a giant sea monster!” Dipper recounted his brush with death on the beach. So animated was his retelling that Mabel could almost forget he’d been napping less than a minute before. After finishing his story, he grabbed one of the nearby books and pointed to an illustration. “That right there is what I saw.”

Mabel put on her glasses to squint down at the page. There was a sketch of a hideous beast rearing out of the water. “Looks like a catfish and a killer whale had a baby.”

“It’s known as a Prister. Rather odd to find it here though.”

“Why’s that?”

“Because the Prister was an ancient Norse myth, from around a thousand years ago.”

“So the question is, what’s an ancient Norse sea monster doing in the north Pacific? And how does the little foot man fit into all this?”

“Little foot man?” Dipper understandably asked. Mabel described the freakish cryptid, declining to mention her awkward accidental home invasion and Toni’s weed den. Dipper flipped through the pages of his book, a catalogue of famous mythical beings from history, before finding a picture of an old tapestry. “That is a Sciapod,” he read from the text. “A single footed race of people, first described by the Greeks. Pliny the Elder said they came from India, bla bla, there’s a bit about using their foot as a sunshade, handy.”

“What the heck’s the link then?” Mabel strained to see any connection between the two creatures, which came from entirely separate mythologies. It was even harder to guess what had happened to all the missing kids. Had they simply been eaten by the fish monster?

“I’d certainly like to know, especially since my creature seemingly possessed the ability to vanish into thin air.”

“Maybe there’s some kind of magical source drawing the creatures in?” Mabel offered. “Like a softer version of Gravity Fall’s weirdness magnetism?”

“Could be. But it’s an odd assortment nonetheless. Hey, you still got that tourist brochure?” Mabel unfolded the pamphlet and handed it over. “Let’s see, the campfire and beach were up here…” He marked a cross with his pen. “And you were over in the suburbs. Where are they?”

Mabel tried to trace where she’d been but took off her glasses and shook her head. “This map is too basic. It doesn’t show that part of town in any detail.”

“Then we need a better map, preferably an ordnance survey map with contours and such. You know where all the witness reports took place right? You could mark them down if we had a map?” Mabel nodded. “There could be a pattern to where the creatures are appearing. It’s all I’ve got to go on for now.”

Mabel grabbed Journal 9 off the desk before he could react. “Then I know the perfect guy for the job.”

* * *

Still in the dead of night, the twins crossed the town, ending up at a small stone cottage by the boardwalk. Mabel had yet to explain what they were doing here, but Dipper trusted she knew what she was doing. She bent down by the front door. Her hands moved in a flurry, then Dipper heard a click. She pushed the door lightly open. “Voila!”

“What!?” Dipper hissed. “Mabel, you can’t just go round breaking into people’s houses!”

“Relax, Merc’s out, he won’t mind us stepping in.”

“Wait, Merc? You mean that guy who looked like he could bench press a mammoth? You wanna piss off that rage machine?”

Mabel flicked her brother in the forehead. “Dude, I said relax. Merc’s nothing but a blowhard, the guy wouldn’t dare lay a finger on me. He knows when he’s outclassed.” She headed inside and called back. “Besides, do you wanna solve the mystery?”

“I don’t see how this is helping,” he muttered under his breath before guiltily stepping in. His frustration vanished when he saw hundreds of maps laid out before him. They were plastered on every wall and surface in the cottage. Maps of the whole world, specific countries, even some maps from fantasy series he recognised.

“All the local maps should be in his main room.” Mabel led her awestruck brother into a room that somehow managed to contain even more maps than the previous rooms.

“You weren’t kidding, this guy really loves his maps.”

“Merc lives here with his grandma but don’t worry, she’s as deaf as a dodo.”

“That’s dead as a dodo.”

She shrugged. “Whatever, she can’t hear us, that’s the point. Be as loud as you want.” She picked up a few maps, trying to look for features she recognised from town.

“So, this Merc,” Dipper said aloud as he did the same. “He must have had really weird parents to end up with a name like that.”

“Merc’s not his real name, doof.” Mabel said, and he could practically hear her eyes rolling from across the room. “His real name’s Kevin. You’d think you’d understand that concept, _Dipper_.”

“Alright, so how’d he get the name?”

She shrugged. “It’s just his surname, Mercator. That’s all.”

Dipper’s face lit up. “Oh, now I get it! The maps! It all makes sense.”

“What does?” Mabel’s brow furrowed, she hated it when he acted all super smart around her.

“You’ve heard of the Mercator map projection?” The response he got was a blank look. “No?” His sister shook her head. “You see, map projections are a means of displaying a rounded surface, like a globe, on a flat plain. Mercator’s interpretation was one of the most influential- hey, are you listening?”

Mabel had yawned and gone off to peruse the other maps, losing interest in Dipper’s attempt to explain geography trivia. He sighed and gave up trying to educate his bored student. “Well, it explains his weird fascination with maps at least.”

“He’s always collecting more,” Mabel said as she cleared a pile of maps from off a table. “We’ve all got our hobbies I guess. Hey, hey Dip, get over here.” Her voice was suddenly urgent.

Dipper came over and peered at the map she was looking at. “What? It looks like an old map of Scandinavia. A Carta Marina print perhaps.”

“Exactly.” She pointed to the left side of the map, towards the Atlantic Ocean where, filling the water, there were dozens of imaginative illustrations of sea creatures. One of which was identical to the Prister Dipper had shown her at the library.

“What are the odds of that… horror vacui.”

“Gesundheit. Wanna say that again in English?”

“It’s, uh,” he looked for other examples to demonstrate the meaning, then just turned back to the Norse map, “see the sections on the edge of the map, where things get sketchier?”

“Where all the fantasy creatures are hanging out.”

“Right. Well, old timey cartographers used horror vacui to fill in the blank spots on their maps. Drawings of magic superstitions or fictional places. You know, so the whole map looks as detailed as the parts that are real.”

She snapped her fingers. “I get it. Like putting ‘Here be dragons’ at the edge. Basically, nobody’s been there, we don’t know what’s there.”

Dipper nodded. “And a lot of these on the Carta are interpretations of real sea creatures. See the Sea Unicorn there, that’s a narwhal. This Sea Pig, probably a walrus, or at least some Viking sailor’s half-remembered recounting of a walrus.”

Mabel looked over the map, paying particular attention to the creature illustrations. She chuckled at the cute sketch of a sea cow, a very literal rendition with horns and udders of what might have been a manatee. On completing her observation she frowned. “That’s all well and good, but I’m not seeing that Sciapod thing anywhere. Wait!” She plucked a map off the wall; this one was centred on Greece. “There you are.”

Dipper saw it and furrowed his brow. “Now hold on. This is way beyond a coincidence. Are you trying to say that the creatures on these ancient maps are somehow spawning in town?”

“Maybe. It’s not so out there. But it doesn’t match up. This coastline looks nothing like Sapphire Bay. They’re maps of completely different places.”

“Perhaps the geography’s not the important part. They are.” He pointed to one of the fancy creature sketches. “Oh, oh!” He started scanning over all the maps in the room.

“What now?

“Paz woulda seen it right away.”

“Seen what? Ugh, I hate it when you do this.”

Dipper finally found what he was looking for, a detailed overview of Sapphire Bay, including the surrounding forests and coastline. He cleared a space and slammed it down on the table. “Assuming north as a constant… pass me that Norse map.” Mabel did what he said and watched him line it up above the map of the town. “I think I saw it… yes!”

The outline of the town was still faintly visible through the parchment. Most of the creatures ended up far out to sea. But the Prister was right on top of the place Dipper had seen it. A few more creatures overlapped the town. “There were reports of people seeing something there.” Mabel pointed to another angry-looking fish and Dipper turned to her.

“Mark them on the town map, as many as you can remember hearing about.” She did as he asked, drawing red crosses all over the place over Sapphire Bay. Dipper replaced the Carta Marina over the map. This time almost all the landbound creatures synced up with a cross. He then placed the Greek map over the town. As he expected, right where Mabel had marked her encounter with the Sciapod, the sketch of the creature was present in the same position overlaid on top.

“This is blowing my mind, Dip!” Mabel studied the dozens of crosses, which mapped up to different mythical beings on both maps. “It’s not random after all. Somehow these maps are being, like, superimposed together.”

“Incredible,” Dipper breathlessly said. “This is a really useful find. Wait, that one doesn’t match up.” Dipper tried both maps above the town, but one of the markings Mabel had drawn didn’t seem to fit a creature from either map.

Mabel searched the nearby maps, but none of them seemed to have the exaggerated stylings of the two they’d found so far. One map caught her eye at last. No horror vacui were present, but the details on the map tailed off in one direction. All except for one note written on the far edge.

Quietly, she held it over the map of Sapphire Bay. It was quite a bit smaller than the town’s map, but the note still matched up with her mystery marking.

“What, what does it say?” The steely look on Mabel’s face made him not want to know the answer.

“Well, you were right about one thing.” Mabel showed him the map and read aloud what the note said. “Here be dragons…”


	5. X Marks the Spot

The next day, after resting the night at Mabel’s beach house, the twins headed back into the forest. This time they had a clear destination and purpose, no more wildly searching about. If their hunch about the maps was accurate, then they needed to neutralise the threat.

Checking his compass and the old Norse chart liberally ‘borrowed’ from Merc’s collection, Dipper ascertained their location. “Alright, we’re nearly in the vicinity. Weapons ready.” The pair of them unslung bows from over their shoulders and held them ready.

Mabel twanged the string a few times, testing the tension. “I miss Ford’s old crossbow. Much easier to aim, though Pacifica’s the real crack shot.”

“We’ve got our training at least. You still remember Wendy’s lessons?” His sister nodded, recalling the time many summers ago when their old friend had taught them some rudimentary archery skills. “Right now I’m missing her more than usual. She’d have loved a hunt like this.” Dipper’s tone was moodier than Mabel was familiar with.

“Hey, focus Dip. We can remember her later. We need to pay full attention, or the creature might get the better of us.” Dipper understood the seriousness and straightened his bow stance. Then Mabel scoffed. “Still can’t believe we’re hunting an actual, honest-to-god dragon. Remind me why you said we couldn’t bring guns?”

“They’d be too loud. We don’t want to spook what’s lurking out here. The bows are silent. Besides,” he said critically, “you’re trigger happy. Anyway, you’ve got your gauntlet.” 

“That’s true.” She turned her wrist over. Attached to her bracer was her grappling hook and a small projectile launcher. Today the launcher was filled with a potent tranquilizer serum. Their arrows were also tipped with the same substance, but Mabel’s gauntlet contained a concentrated dosage.

If they could stun the beast with their arrows, she could get in close and administer the full blast and knock out their quarry. Hopefully, they would avoid a repeat of Dipper’s encounter last night, where he almost ended up as fish chow.

Mabel nocked an arrow and drew it back. Creeping through the brush, she didn’t see or hear anything untoward, so loosened her grip. “You know, when this is all over we should kick back, have a movie night or something.”

“I’d like that.” Dipper thought about that for a moment. “How about Tiger Fist VI: The Punchening? That was always your favourite one.”

“Sounds great, I could do with some epic shlock. Ooh, mustn’t forget, I’ve got to stop by in town first, I’ve gotta drop off Tarik’s mixtape.” Reaching into her jacket, she retrieved and spun a glass case around between two fingers.

“Who uses CD in this day and age?” Dipper asked incredulously.

“Tarik’s old school. Some sick beats on this thing though, surfer boy’s got good taste.”

“Sounds like you’ve settled pretty quickly here,” he mused. “Lots of friends, you know the town well.” Mabel thought she detected the slightest hint of envy in his words. He had always been the less socially comfortable of the two of them. “Hey, I meant to ask earlier, how’d you get such a nice beach house anyway?”

“That’s easy,” Mabel brushed off. “I have a whole network of contacts, all across the country. They pitch in from time to time.”

“Oh right, you mean your old hippie commune buddies. I shouldn’t be surprised; you move around so much. Think you’ll ever settle in one place?”

Mabel wondered if he was angling to get her to move to Gravity Falls once and for all. It wouldn’t be the first time he’d made such an offer, and the idea was tempting. Yet some itch deep in her spirit to travel onwards had always kept her from accepting. There was just too much elsewhere in the world to keep her occupied.

Dipper kept nattering, not realising how much thought she was giving it. “There’s lots of room for you in town of course. Paz and the kids always love having you around. Not to mention all the nostalgia, and old friends-“

“Dipper?” Mabel abruptly whispered.

“Huh, yeah?”

“Shh. I hear something.”

“Oh.” Dipper lowered to a crouch and readied his bow. There was a sound like a snake’s hiss coming from nearby. “I see something moving, through the trees, there.” He aimed his shot through the rustling branches, hoping to fire off a warning.

Mabel let off an arrow first. It zipped through the air and into the bushes, and they heard the sound of an impact. “Yes!” She ran forwards without any kind of self-preservation instinct, determined to get a glimpse of the creature.

She thrust a bush aside. There it was. The dragon had an elongated neck like a swan, with a small head flailing about at one end. Her arrow had landed near a pair of stubby wings which supported the neck halfway down. The skin was a bright red unlike any seen in nature, with the lower half of the creature was obscured by yet more foliage.

“More of a wyvern I’d say.” Dipper crept up beside her. “See, no front legs, just a pair of wings, bat-like.”

“Now’s not exactly the time for a biology lesson, bro.” She raised her bow again to finish the beast off, but Dipper forcibly lowered her arrow.

“Wait, we can’t just kill it. This is a unique specimen. We need to study-“ At that moment, the dragon’s eyes fixed on the twins. Its jaw gaped open and let loose a gushing torrent of white smoke. The twins dived to either side, feeling the heat from the blast. “Not a traditional fire-breather then!”

“Oh lord.” Mabel wasted no time in grabbing an arrow and firing again at the beast. Her shot was true, hitting one of the wings.

Dipper finally saw the need to defend himself and let off his own arrow. It was weaker than Mabel’s shot, and bounced off the hardened skin of the head. The dragon crawled forwards using its wings, but the twins continued to fire arrow after arrow, so they stayed out of range of its teeth.

“I think we’ve nearly got it,” Mabel triumphantly said as she circled round, firing again and striking the throat of the mighty creature. It reared up and roared, before the flimsy neck flopped down.

“Woo, that’s it!” Dipper cheered. He stepped up to closely examine the dragon, heady with the thrill of success. “That wasn’t too hard.”

Mabel was more cautious, always mindful that strange and new creatures could often surprise you in unexpected ways. “It looks unconscious at least.” Her eyes traced along the neck, past the wings. “Where’s the rest of the body?” It seemed like the creature was _all_ neck. She couldn’t see any body at the far end, it just snaked off further into a small hole in the ground. Actually, it was more like a cave entrance.

Sudden movement came from the darkness within, and Mabel’s face paled. “Oh dear.” She backed up to Dipper quickly. Together they watched the far end of the dragon begin to write around. From out of the cave came a second long neck, curled in an angry expression. Then another. And another.

Finally a massive rounded body emerged into the daylight, with multiple dragon necks whirling around each other and casting jets of boiling smoke into the air. Each dragon looked at the twins in turn before all were united in purpose.

Mabel reacted seconds before the mass of tentacles shot at them, pushing Dipper to the side. Getting up quickly, he tried firing an arrow at the central mass. It was lost in the swirl of dragons, barely affecting the speed of the creature.

“Forget the bow! Run!” Mabel tossed the weapon aside and reached into her jacket. Dipper saw a stubby metal device in her hands before he was deafened by several loud gunshots. “I said run! Vamonos!”

This time he did as told, letting Mabel cover him with her surprise backup weapon. Her bullets scarcely did more than scratch the fearsome hydra, and she quickly likewise broke out into a sprint. The one advantage they had was that the dragons were slow, constantly getting caught up on each other and having to drag the massive bulk where they all joined up.

That gave Dipper an idea. “Mabel, tangle them up! Your gauntlet.”

Following his instruction, she pivoted round, pulling the trigger on her gun ineffectually a few times to give the dragons the air of superiority. The moment they were in range, she dropped the pistol and lifted her wrist. There was a puff of air and her grappling line went sailing through the air. She whipped her hand round when it was at the full length, tying it around the base of the many snarling dragons’ necks.

The great bulk chasing them stopped, with each individual dragon too caught up in trying to free itself from the great knots Mabel had just created between them. She wrestled to keep the line tight, causing further discordancy and the dragons wrapped themselves around each other again and again. Dipper ran over to help, using his recently found reserves of strength to aid his sister. Eventually the collective energy of the beasts gave out.

With a simple tug, Mabel yanked them all down to the forest floor. Nearly out of energy, she charged forwards and fired the tranquiliser serum at the base of the necks. The exhausted dragons all fell still as one, collapsing into a mess of necks and wings.

“Woo!” Dipper yelled. “We did it, high five!”

Mabel breathed deep and stepped away. “Now that was a hunt Wendy would be proud of. So what is this goddamn thing?” The sound of multiple snoring dragons was started to become overbearing.

Dipper already had his journal out and was eagerly sketching the fallen titan. “I’ve seen medieval drawings that are similar. You know, you put a mass of writhing heads at the edge of a map and don’t bother with the bodies. Saves the artist having to do a full sketch.”

“I guess that confirms the theory then.” Mabel tapped the creature with her boot, almost expecting it to pass right through. The idea that these monsters were being spawned from Merc’s old maps somehow was still hard to wrap her head around.

Her foot suddenly hit hard ground as the unconscious body of the dragons became intangible. Unable to look away, she stared as the whole enormous mass disappeared as it was consumed in golden light. “What was that?!”

Unphased, Dipper was still focused on the journal. “I get the feeling these creatures come and go, spawning and vanishing in cycles. Maybe we can check the cave it was dwelling in.” He didn’t move, content to leave Mabel to investigate.

She left him sketching and peered into the gloom. She gave a sharp intake of breath that drew Dipper up from the page. “What? What’s wrong Mabel?”

“There are skeletons in here.”

Dipper rushed over to her in an instant. True to her word, there were piles of bones, ribcages and skulls, lining the floor of the stone cave. He wanted to see how far back they went, so pulled out a flashlight. He counted enough bones to be from about a dozen different bodies. 

“It’s not all of them,” he said with a gulp, referring to the missing people. Clearly the dragons weren’t the only creatures causing people to go missing. He panned the light and a chill ran down his spine. “Oh Jesus, there’s a… fresh one.”

Mabel threw her hands over her mouth. Tears began flowing down her face. “It’s Tarik.”

Dipper shone the flashlight on his face, then quickly switched it off. It was the same face he remembered seeing only yesterday, vibrant and alive on the boardwalk. Now reduced to nothing but leftovers in the larder of theses monstrosities. “I’m so sorry.” He was only just able to get those words out without breaking down himself. He turned away. “We have to get out of here.”

“What?” Mabel shouted, offended at the idea of leaving.

“Those dragons might return. You see what they could do to us.” He angrily gestured down at Tarik’s remains. “Please Mabel, we should get somewhere safe.”

She nodded, but still walked over to Tarik’s body. Wordlessly she placed the CD case down atop his body, then ran from the cave, unable to bear the sight of it for a moment longer.

* * *

“It’s worse than I thought. They’re not just missing, they’re… gone.” Mabel stared down at the waves, speaking with barely a hint of emotion.

“Almost certainly,” Dipper stated, trying to be rational. “The sea creature I ran into, or others like it, they must be causing the disappearances. We know that now.”

“But it’s so horrible. Why? Why is this happening? It was just tourists – strangers – before, now Tarik. He was a local, born and raised in Sapphire Bay. All his life…”

“I don’t know,” Dipper weakly said.

“I’ll have to tell his dad. God, this is awful.”

“I understand.”

Mabel whirled round on him. “No you don’t! This is my life, Dipper! This world is unfair and unjust. People are hurting all over, and I try to stand up to it. I try to make it a better place. And that means having to confront things like this. You’ve never had to confront it up close.”

But she already knew that her words were false. The shared memories of Wendy struck again and this time she couldn’t not dwell on the sad parts. “I’m sorry, I didn’t mean-“

“It’s fine. In the past.” Dipper gave her a quick hug. “We’re going to sort this out, you and me. We’ll stop anyone else suffering the way Tarik did. I promise. Come one, we fought and beat a dragon today! Who else is better for the job than us?”

That elicited a small laugh through the tears from his sister. Then she pushed herself out of his hug. “Uh, Dipper, your crotch is rumbling.”

“My what?” he said, bemused. “Oh, it’s my phone vibrating.” He pulled it out to check his alerts. “Ah, it’s from the library. While I was there I set a search running on their database – their system is ancient. I wanted to collate all the missing people reports. Thought we could look for patterns in the victims maybe.”

“Most were college students,” Mabel said, wiping her eyes. “I don’t think anyone else has disappeared… except Tarik.”

“But there might be more to it than that. In any case, knowing when the cases started will be a useful clue into finding out why this is all going on in the first place.”

“If you say so.” She lifted her arm and gestured back towards town. “Library then. And we’d better hope we find something solid to go on or we really have hit a dead end.”


	6. Mappa Mundi

Arriving back at the library just as a light rain began to fall, the twins stopped up short by the entrance as the hulking form of Merc blocked the door. “No getting away from me this time, thief,” he said in his gruff voice.

Mabel crossed her arms and sized him up. “Outta the way Merc, we’ve got important work that needs doing in there.”

“You can’t get in anyway,” he shrugged. “Library’s closed. You can’t escape, May. Now fess up.”

“Hey, that’s my sister you’re accusing!” Dipper stood tall to defend Mabel’s honour. He couldn’t stand people bullying her. Even confronted with Merc’s impressive musculature he wasn’t intimidated in the slightest.

Merc ignored his presence and focused singularly on Mabel. “Once is enough, but twice? This time I’ve got you, for sure.”

Mabel pushed Dipper gently out of the way, impressed by his chivalry but not requiring anyone to defend her honour. “Oh yeah?”

“Oh yeah.” She was about to ask Merc what proof he possibly had when he jiggled her lockpicks in her face. “Got you.”

“Ah. Oops”.

Dipper facepalmed and sighed. “Should have known. Fine, we’ve got your stupid maps, have them back.” He reached into his jacket and pulled out the sheaf of maps from beside his journal.

Mabel handed them over to the map lover, who quickly ruffled through the ancient parchments. “That’s a start at least. I might actually get round to letting you off the hook for all this. Now hand over the other one.”

“Other one?” Mabel cocked her head in such a way that disavowed any possibility that she was lying. She was just too genuine and even Merc could see that. “These are the only ones we took, honest.”

Still, Merc turned to Dipper for an explanation. “Look, I know what maps I’m missing. Hand it over and maybe I’ll forget about all this.”

“I don’t know what to tell you man, we gave you all the ones we had. Now, we really need to get into the library, so if you could just step aside…” He edged around Merc’s implacable form and gestured to the locked door. “Mabel, if you please.”

Mabel threw an apologetic grin to her friend and got to work on the lock using the very tools he’d brought her. “Funny though, Sam doesn’t usually lock this place up. She’s supposed to stay on shift ‘til midday.”

“Maybe she went for a nap, the girl looked like she was overdue some major sleep time,” Dipper said. The door clicked and they passed inside. “We won’t need her help anyway. My request was all on their computer system.”

They sat down at one the old boxy computers available for public use. After an agonisingly long start-up, the machine was up-and-running and processing Dipper’s inquiry. His search on the database sent in the early hours of the morning had finally come through. Scans of all the missing people posters were at his fingertips at last.

“Alright,” Mabel said. “Dragons and sea monsters are one thing. Now for the nitty gritty of finding out what ties it all together.”

Dipper started scrolling through each report. “Let’s see, oldest reports seem to start around six months ago… no obvious link between the cases.”

Mabel watched as a stream of faces flew up on the screen. Men and women, of various different ethnicities, but all were around 18 or 19 years old. Almost certainly they were all from out of town as well. No explanation for how Tarik’s death fit into it all.

The information on each poster was basic, with a mugshot of the missing kid, a name, and the date of disappearance. These were the one fig leaf that the town authorities were using to convince people they were actually working on solving the problem instead of trying to quietly sweep it all under the rug. Print a snazzy official poster and leave it at that. Now at last Mabel was seeing every individual who’d vanished, every life snatched away.

Dipper suddenly stopped scrolling through the posters, reversing and scanning back up a few. “Wait, this can’t be right. This poster’s date must be incorrect. It says 2014.”

“But that’s over a decade and a half ago.” Mabel looked at the poster in question, showing a fuzzy photo of an African American teenager. “Old case. Maybe it’s unrelated…” Her eyes turned down to the name, and she audibly gasped. “Oh my god.” Dipper looked at her quizzically. “This guy, Joshua Taylor. I recognise his surname. It’s the same as Sam’s!”

“What, your friend Sam? The librarian?”

“Merc said something about her taking his maps…” Mabel muttered to herself. She paced around, putting things together in her mind.

“What are you saying? Are you on to something?” She started sprinting out the library and he called out. “Mabel, wait!” He pressed the print key on that specific poster and grabbed the copy before running after his sister.

She was already in the midst of another ‘friendly debate’ with Merc, her finger aggressively pointing at his chiselled chin. “Don’t make me tell Toni your real name’s Kevin! I know you think she’s hot.”

“Ok, ok, sheesh! Relax May.”

“Then talk! Tell me about your missing map.”

“It was an antique, one of my more priceless artefacts.”

“Well?” Mabel tapped her foot. “Don’t spare the details.”

“It was a map of Sapphire Bay from the mid-1800’s. Only about a decade after the town was founded. Beautiful old cartography. And it was stolen a few months back.”

Merc seemed incensed again, about to go off on another loud rant, but Dipper stepped in first. “What’s Sam got to do with it then?”

“I saw her with the map!” he said, like it was a definitive proof. “The other day, she was out in the woods alone. Oh, she claimed it was something else, but I know what I saw.”

The twins shared a look. It all led back to the maps somehow. The missing people, the creatures. Mabel spoke the obvious. “We need to talk to Sam.”

* * *

Dipper had no complaints this time as they raced back to the house on Mabel’s bike. The moment they pulled to a stop Mabel was off the bike and marching to the front door. “Quick in and out, grab some supplies, then we go find Sam.”

Before entering the beach house, Mabel pulled her pistol out from her jacket. She checked the clip, then reloaded.

Dipper stared at the process, at how emotionlessly she carried it all out, with an air of disappointment. “I thought I said no guns last time.”

“Yeah, and last time we were nearly burnt alive by dragon smoke. It’s just a precaution.”

He stepped in front of the door and addressed her sternly. “You’d really use that thing on your friend?”

“It’s for if we run into another mythical monster, dummy.” She half-turned her face away. “Unless Sam is really causing all this out of malice. If she’s turned bad or whatever.”

“You’ll do _whatever’s necessary_ ,” Dipper said solemnly. “Let’s play this cool, alright? No guns blazing, we talk to her first.”

Mabel deflated and tucked the gun away. “Fine. We’ll do it your way. It’s just… another betrayal. Why can’t I ever trust anyone, people are always hiding things. I wanted a quiet getaway in this town, I wanted to like Sam. She was cool and smart. Now all this… ugh.”

Dipper hugged his sister again, calming her nerves. “Come on, let’s get this over with.” He opened the door and stepped inside her house, leaving Mabel on the porch to unwind.

She ran a hand through her hair, remembering all the times she’d spent with Sam and her other friends. She liked to read books on the beach but go crazy partying every free night she could in the clubs. It was fun. She didn’t seem like someone who could casually summon an army of monsters.

Her reverie was shattered when Dipper’s sudden scream came from within. Instinctively she readied her pistol and charged in after him without hesitation. If he was in danger she would be there for him.

The living room and kitchen were empty, but she spied movement out of the large bay windows. Out on the balcony Dipper was lying on his side, bound by ropes and a cloth gag covering his mouth. He mumbled when he saw her and tried to wriggle free.

A foot came down on his side, making him stop. Sam was standing over his prone form, a serious look on her face. “Knew someone would find me eventually.”

Mabel fixed the gun right between Sam’s eyes. “Give me a reason not to use this, go on.

“Please, May, lower the gun. We can talk-“

“Samantha!” Mabel yelled, gripping the gun tightly with both hands and keeping it aimed at her friend. “Let him go!”

“I didn’t want to have to do this, honestly.” Sam raised both hands as if to surrender. She smiled sadly and Mabel’s resolve wavered. As she slightly lowered the barrel of the pistol, Sam’s hands shot out and a burst of bright light cast the gun from Mabel’s grip.

Mabel dived for the kitchen counter and ducked behind it. Another spark hit the tabletop right by her head, showering her in plaster and dust. Dipper’s muffled screams from the balcony were met with a thump. “Shut up!” Sam called over to Mabel. “Please, come out. We can discuss this.”

Her back to the counter, Mabel breathed rapidly and tried to stall for time. “Why’d you help us? You gave us those leads on the missing people. Why do that if you were behind it all along?”

“What are you talking about? That has nothing to with this.” For an instant she thought she heard genuine confusion in Sam’s voice. 

Mabel chose that as her one moment to strike back. She launched herself up and smoothly rolled over the countertop, sparks impacting all around her. With a clear sight on Sam, she crouched and yelled a single word. “Incendo!” A shroud of flames leapt up around Mabel, absorbing Sam’s magical attacks. Sam stared, boggle-eyed as the flames gradually vanished. “That got your attention?” Mabel said icily. “Guess what. I know magic too. Not the zappy hand bolt stuff, but still. You wanna talk? Now we’re on even playing field. Let’s talk.”

Doubt raged across Sam’s face as she wrestled with the indecision. Mabel thought several times that she wanted to lash out again, or that she would simply flee over the balcony and take her chances in the water below. But then she lowered her head, clearly exhausted, and Mabel too softened slightly.

“Alright May. You win. What do you want to know?”

“I mean,” Mabel casually started, “I wanna know a lot of things. Why I always lose one sock after a wash. Why platypuses exist. Why Toni never asked you out even though she’s obviously into you and it’s getting kind of hilarious at this point.”

“Be serious,” Sam said with gritted teeth.

“I think the thing I want to know most is what _you_ think you’re doing. Merc told us about the map.”

“Oh. You mean this.” She unfolded a piece of frayed brown paper and held it up. Mabel’s eyes fixed upon the curving outline of the coast and the settlement laid out along the north side. “You’d think Mercator wouldn’t miss one little map.”

“Hey, you know Merc right, that dude’s intense about his stuff.” Mabel said it jokingly, trying to calm the tension and ever-mindful of her brother tied up on the decking.

She tried to edge closer, but Sam clenched her fists. “It told me you’d be here. The map ritual finally worked. I was so hopeful. But it was just to warn me. About you.” She glared at Mabel with eyes filled with hate.

“What’s this all about, Sam? You get a kick out of all this violence? You got rid of your brother all those years ago and now you’re out for more blood, it that it?”

“I loved him!” she angrily shouted, riled up by Mabel’s taunts. “We were family. Josh was always there, my older brother looking out for me. We were good.” Sam held out a hand, collecting a small trickle of rainwater. “It was raining when he left. Just like this. Not a thundering storm. Just grey and miserable.”

Sam’s voice wavered. Mabel listened attentively, not wanting to interrupt this personal account. “We found his note in the morning. I was only 10 years old. Can you imagine that May? The person you most care about in the world, and he can’t even tell you in person why he’s leaving. We never knew where he went after that, and he never came back. Never.”

“So now I’m a witch,” Sam finished with a shrug like it was the most obvious thing in the world. 

“Oh, well, when you put it like that it all sounds _totally_ understandable,” Mabel replied with a roll of her eyes.

“It was the only thing I could think of to do. To bring him home.” Sam thrust the archaic parchment in Mabel’s face. “This map is incomplete, see. There are blank spots at the edges. Unmapped places. I found this old book, in the library one day, filled with spells and incantations for someone with the talent to act on them.”

“That’d be you?” Acutely aware that Sam was running out of explanation, Mabel knew needed to figure out how to overpower her before she got tired of this game. Her gun was off in the corner. If she leapt for it she might reach it but then she’d be exposed on the floor. She didn’t know an offensive spell that wouldn’t hit Dipper in the crossfire.

“I was filling in the edges of the map. You understand, May?” Sam was staring at the map, her words almost mechanical. “I could find him, if only the spells would work. I keep trying but Joshua is still lost to me.”

“Uh-huh,” Mabel nodded vigorously. “Go on, tell me more. All about those creatures you’ve been summoning, I’m sure it’s fascinating.” Maybe her grappling hook, trip her up somehow like the dragons? Up close she might use hand to hand combat. Or a chance to free Dipper, then-

“Creatures?” Sam’s confusion, as before, seemed real.

Mabel’s mind switched from planning strategies to trying to understand her friend. What did she know? Was this another lie? She’d hidden this vengeful side of herself before. It couldn’t hurt to be direct. “You know. The whale monsters. The strange things living at the edge of town. The _giant dragons!_ ”

“What on earth are you on about. I haven’t done anything. I try, I repeat the rituals all the time, but the spells don’t work.”

“Trust me, they work alright. They aren’t doing what you think they’re doing though!”

“You’re talking nonsense!” A vague glow began to form around Sam’s fists, which were clenched even tighter. She was about to lash out, a provoked animal reaching her limit.

Mabel went for her last resort. “Please, stop it Sam! Tarik died for this!”

“What? You’re lying!” Sam backed up against the wooden balcony. Beneath her curly hair, frizzy from the rain, was the face of a frightened girl missing her brother mixed with a powerful force ready to strike. “I’m not dangerous!”

“Coulda fooled me.” Mabel side-eyed Sam’s hands, wary of her magic attack. There wasn’t going to be much more planning time. It was now or never.

Sam wringed her hands, endless emotions vying for supremacy. Then she held up the map, a wild grin spreading. “I’ll show you. It’s harmless.”

Dipper’s eyes suddenly bulged out and he strained against his bonds anew. He tried to communicate to Mabel, mumbling through his gag. Think, what did he know that she didn’t? He’d done most of the research into the creatures, studied the old maps. Did any of them match up with this location…

“Watch…” Liquid light flowed from Sam’s hands and enveloped the map of town.

“Sam, stop, please!” Mabel cried out, cognisant of how much danger they might be in.

It was too late. The coast of the map lit up and several bright points all around shone. Including one along from the town. An isolated little spot. The perfect place to build a beach house.

“See, nothing! A stupid glow and that’s all!”

An unearthly howl unlike anything they knew reverberated through the beach house. A whale’s sonorous moan but humanised in a way. Like someone trying to imitate a whale call. Badly.

Sam stood frozen on the spot. She pivoted to look at the ocean. The crashing waves down below were intersected by a parallel line, moving directly towards them. A dagger cutting through the water, leaving a trail of spray behind it. Then a torpedo of death launched out of the ocean, completely covering the height of the cliffs. Sam leapt aside as the fleshy body impacted. 

Mabel raised her arms, blocking splinters of wood from the now broken balcony. The creature, flopping on the wooden decking, smashed the bay windows, raining glass all around Sam and Dipper.

Lowering her arms, Mabel finally got a glimpse of the sea monster, right before it darted back off into the ocean. The body was built like a shark’s, lean and efficient. So far, so mundane. A sharp fin, serrated and deadly, shot out of the striped back. But it was the face that sent a shiver down her spine. Wide eyes, bulging like those of an owl sat at the centre of a round face surrounded by a mane of flared thrills. 

As the aquatic attacker rounded, it fired out again at the beach house, a razor-sharp snout leaving the water first. More of the balcony broke away and fell into the distant sea. The creature, ungainly on land, turned itself. Ignoring Sam completely, the piercing eyes fixed on Dipper. He crawled helplessly away.

Before it could lunge, Mabel leapt for her pistol. Unleashing a hail of bullets that seemed to barely scratch the thing, it at least had the effect of sending it off the cliff again. It rolled in the air and splashed back down, but she had no assurance that it wouldn’t strike again. Like with Sam, she had to analyse the threat. That wasn’t her strong suit. She usually left it to Dipper.

Dipper. Wait. That was it. This creature – whatever it was, spawned by Sam’s magic – it was going for Dipper, charging specifically at him. That’s what he’d been trying to warn her about. Not only the location, right by a creature spawning point, but himself too. He was from out of town, visiting Sapphire Bay. If there was one consistent pattern to all the disappearances apart from Tarik it was that all of them were visitors passing through. Not long-term residents like herself or Sam.

As she assumed, the form of the monster once again launched towards them, relentless and powerful in its leaps. This time she was ready. She threw her arms around Dipper and the two of them rolled out of the way right as the creature embedded itself in the beach house, tearing planks of wood and causing the whole balcony to shake. It couldn’t take many more hits before completely collapsing.

Mabel grabbed Dipper’s gag and pulled it off his mouth. The first words to leave his lips were a breathless exultation directed at their attacker. “It’s a Ziphius!”

“That doesn’t help us kill it!” she replied in frustration, furiously untying his bonds. “Why couldn’t it have been a friendly sea cow? Any help from you, Sam?” Her friend was stock still, in complete shock and prone on the decking.

“The map!” Dipper stated. “It’s all about the map. It’s linked to the others, forcing the creatures into existence.” He rushed over to Sam and tried shaking her. “Come on, tell us, how do we stop this?”

She didn’t reply or even acknowledge him. The map lay beside her, glowing still with its network of ley lines. That seemed to give Dipper and idea. “Sam, use this!” He reached into his pocket and held the constellation marked cover of Journal 9 right in her face, tapping it persistently. “See it? Do that spell again, right here.”

For an instant Sam seemed to come back to life. She accepted the journal and stared in rapture at the stars on the cover. But time was of the essence. Before she could even start to enact her spell, the Ziphius struck again. Mabel grabbed Dipper out of the way, throwing themselves over to whatever platform still standing they could make it to. She fired another desperate bevy of gunfire, but the effect was only a few weak puffs of blood. The twins embraced and backed up in the last surviving corner of the balcony. 

“This is it, Dip.”

“Oh god. At least we solved this thing, eh Mabel?”

“Yeah. We did.”

That was some small comfort at least. The Ziphius dragged itself painfully slowly, almost as if it wanted to prolong the torture. There was nary a sign of Sam, whether she’d even avoided the crash. A slit beneath the creature’s snout opened revealing a vast dark pit from which there seemed no escape. Both twins let out a scream as death marched unfailing towards them.

Then the creature reared up as if to strike. But the blow never came. Instead, it writhed about in a panic, golden light engulfing it. “Now’s our chance!” Hand in hand, Mabel led Dipper around the flailing monster. It fell onto the balcony, smashing it to shreds at last and falling into the abyss below.

The Ziphius never struck the water. It vanished into golden light long before that.

Brushing shards of wood and glass off themselves, the twins saw Sam, kneeling over Journal 9, palm outstretched. Beside it, the map of town was nought more than an old bit of parchment threatening to blow away in the rain.

“I’m sorry. So, so sorry,” Sam whispered. Mabel walked over to her. Dipper expected his sister to strike out, to take revenge for all the lost souls. She simple hugged the shaken girl, holding her tight in that familiar Mabel way.

Dipper surveyed the damage, half of the house torn to pieces, debris strewn everywhere. And he smiled. “All in a day’s work.”

* * *

“I think I figured it out,” Dipper said an hour later, pacing back and forth beside the aftermath of the wrecked veranda. A few rays of sunshine were finally breaking through the gloom high above and casting him in a halo of light. “While I was tied up. The description of Sam’s spell, all our encounters, the repeating patterns. It all made sense.”

Mabel and Sam, sat together on beanbags and nursing ice creams (Mabel’s idea to make Sam feel at home), nodded gently for him to continue.

“See, Sam’s spell was meant to unfog her map, so to speak. To bring her brother back to her by clearing away the unknown space between. Except that’s not what happened. Sam, the way you talked, you didn’t just want Joshua back: You were angry at him.” She looked away. “He left for whatever personal reason he had, and you saw that as him abandoning you. So when you used your spell, all that ended up happening was that you repeated the cycle.”

“The missing college kids,” Mabel stated. She saw Sam growing uncomfortable and rested a hand on her shoulder. “Hey, it’s ok. It wasn’t your fault. You didn’t know what you were doing.”

Dipper continued, pacing faster and he laid out the whole story. “Instead of reaching into the edges of the map, the magic imbued the map with metaphysical energy. It bonded to the other maps it had been in proximity with in Merc’s house, forming a link. Those monsters we saw – the Prister, the Ziphius, the dragons, even the Sciapod – they were a catalyst.

“Out of towners suddenly vanishing without a trace,” Mabel concluded. “People matching Joshua’s age were brought here, and through your spell you repeated the same loss you went through.”

“Oh god.” Sam buried her head in her hands. “I’m so stupid. I only wanted my brother back. I never wanted to cause so much death.”

“You made a mistake, that’s all Sam.” Mabel gently made Sam look at her. “Don’t blame yourself, magic can be unpredictable. You didn’t do it on purpose.”

“I carried around a ball of resentment inside me for fifteen years. I hated him. But I still wanted him back. I don’t know if I can ever let that hope go, that he might someday walk back into my life.”

“Hey,” Mabel said, “what you said earlier, about your brother leaving. I do know what that’s like Sam.” She looked to Dipper, who nodded for her to go on. “I didn’t understand at first either. Sometimes though you need space. Being together constantly, it can be suffocating. But we took some time apart to live our own lives and came to see the other’s point of view. Now we’re closer than ever.”

Dipper continued, speaking as softly as he could. “This might not be what you want to hear Sam, but you can’t force someone to come back into your life. If your brother truly cares about you, he’ll come back on his own. Otherwise you shouldn’t give him another second’s thought.”

“Thanks,” Sam sniffed, wiping a tear off her face. “At least it’s over now.”

“Exactly,” Dipper grinned. “You ended the suffering, when you used my journal as a source rather than the map it stopped the whole shebang.”

“And you’re sure there’ll be no unforeseen side effects of that?” Mabel asked with a raised eyebrow.

“Yes, I’m sure.” He pursed his lips and shook the journal, dissipating the last of the golden glow. “Totally. Maybe the odd extra creature manifested back home, but it’s Gravity Falls. That place is used to weirdness.”

Sam stood up from her beanbag, determined look on her face. “I know what I have to do now. Since I started all of this I should try and do what I can to fix it. Like you did, May, I have to try and sort out all the disappearances, try to tell the families what happened. Even poor Tarik.” Her composure wavered and she let out more pained sobs. “It’s the right thing to do.”

“Hey, that’s one question I still have, Dip.” Mabel spoke quietly, still dealing with the events herself. “Why did Tarik die? I mean, the dragons were pretty fearsome, but he was a local. It doesn’t match up.”

“Hmm, beats me. Unless perhaps something was interfering with the creatures’ natural instincts. Chemical runoff perhaps, something like that.”

Mabel snapped her fingers. “Oh, I think I get it. Toni’s weed den!”

“Toni’s what now?” Sam said with a disbelieving chuckle, ending her sullen mood.

“I’ll tell you all about it out later.“ Mabel flashed her a wink. “You could use some unwinding after all this.” She turned to her brother, who was blushing like a kid who shouldn’t be hearing all this ‘scary drug talk’. “One of the creatures must have busted the lock and snuck in. The confusion from the drug, that’s why it killed Tarik.”

“I guess that’s all solved then.” Dipper made a note of it in his journal. “Another successful Mystery Twins operation. I just wish-“

“Yeah,” Mabel cut him off, “that it had a happier ending. That everyone could have made it out. That’s life I guess.” It was a cynical note for Mabel, but not totally unexpected. Years combating injustice sometimes left her jaded to the nature of the world.

Then she smiled, a bubbly ray of sunshine again. “We can move on at last though. Sapphire Bay is safe again.”

Dipper went silent for a moment, before calling out to his sister. “Hey, can we talk for a sec? Twin to twin?”

“Sure Dip.” She turned to Sam and smiled. Her friend understood and gestured for her to go.

Dipper was waiting out on the remnants of her balcony. “So what’s your plan now? Stay here? Move on to another cause?”

She shrugged. “I dunno. I’ll probably stay for a little while, help Sam try and come to terms with all this. Sort through the mess of all the people we need to inform about the missing kids.”

“That’s what I love about you Mabel.” He leant out on the fragmented balcony. “You have such a pure spirit, always helping out.”

“Hey now, you used to find that annoying.” She blew a raspberry. “Fatherhood’s really mellowed you out.”

“Ha, shut up.” They playfully bumped each other’s sides. Then Dipper looked down at the ocean waves, serious again. “A shame it’s over in a way. Was getting used to working as a team again.”

“Who said anything about it being over, mister? We’ll see each other again in no time, I know it. Don’t worry about me being lonely.”

“Yeah, I know you, always making new friends.”

“Go be a dad, Dip. I’m sure you’ll be wonderful at it.”

“Awkward sibling goodbye hug?”

Mabel thought for a moment, then smiled wildly. “Duh.”

The twins hugged, ready to split apart yet again. But they knew this wasn’t the end. Sapphire Bay’s troubles had started when one family had been broken apart. Sam had never processed it fully. But now with Mabel’s help things could begin to heal. Their union as twins had followed a similar course, going through so much and coming out stronger

And Dipper would head home with his journal. He had a whole new story to tell his family when he got there. That was the best part, knowing the map would never be completely filled in. There were always new places to explore, new mysteries to discover, and new stories to tell.

**Notes for the Chapter:**

> So this is the finale of this current little story. As far as future plans go, I'm certainly considering more shorter instalments like this one, it was a lot of fun to write. For specifics, I have some ideas for an idea about Dipper bonding with his daughter on a camping trip whilst Pacifica deals with some other situation at home. Nothing concrete yet, still cohering ideas into place.
> 
> Til then, hope everyone liked this story, it really kickstarted my writing again after completing my last mega-fic


End file.
